1. Technical Field
The invention relates generally to irrigation controllers providing microprocessor control of watering stations, and more particularly to a new and improved display arrangement for such a controller.
2. Background Information
The display on an irrigation controller enables a user to interact with the controller for programming purposes. It displays alphanumeric character strings related to various watering schedule parameters so they can be monitored and changed as desired. This is sometimes done by manipulating various front panel controls while viewing the display, and in order to facilitate this process, the display and front panel controls must be carefully arranged.
By way of background, such controllers are used to provide centralized control of watering stations located at remote sites over the field to be irrigated. The controller may include electrical circuitry housed within a stand-alone unit suited for installation at a conveniently accessible outdoor location in or adjacent the field. There, it functions to activate the stations according to a desired watering schedule to provide more effective and convenient irrigation, as well as better water conservation.
Some controllers accomplish the above under microprocessor control. Once preprogrammed with various parameter values, such as the start time, duration, and repetition rate desired for each station, the microprocessor produces control signals that are used to activate solenoid valves at the watering stations. This causes water to flow at each station on schedule with microprocessor accuracy and dependably, while allowing the user great flexibility in prescribing the exact watering schedule desired.
The parameter values are preprogrammed by the user, and this is sometimes done with a series of switches on the controller front panel. The switches may be arranged in a keypad configuration, for example, and the user depresses the keys in a certain sequence that results in the desired parameter values being entered. The sequence sometimes includes depressing a key in order to select a specific group of the parameter values to be programmed, such as the group of parameter values related to a particular watering station, and this requirement results in certain problems that need to be overcome.
For example, the user must recall what keys to actuate to select a desired group of the parameter values, and once the appropriate keys are actuated, the user must remember the group selected. This may seem easy enough, but in the context of programming a controller having multiple watering stations and multiple programming functions that each correspond to a different group of parameters values, errors sometimes occur. Thus, it is desirable to have an arrangement that overcomes this concern.
Although identifying labels adjacent to indicator lamps on the front panel would serve to identify the group selected, this arrangement increases controller size, cost, and power requirements. In addition, the lamps may fail periodically. Thus, this technique is not entirely satisfactory.
Some existing controllers, called hybrid controllers, utilize a rotary switch to provide feedback to the operator. Each position of the rotary switch corresponds to a separate group of parameter values, and each switch position is labeled. Thus, the user turns the rotary switch to the appropriate position, and there it remains to identify the group selected. Other controllers have multiple switches for this purpose of providing feedback.
However, these arrangements are somewhat inconvenient to operate in comparison to depressing a switch. In addition, the contacts of many rotary type switches are prone to corrosive and other damage in the environment common to many irrigation controller installations. Furthermore, the switches must be sufficiently large to be grasped by a user in the field, and this results in a bulkier panel arrangement than desired.
Consequently, it is desirable to have a better arrangement for selecting one of various groups of parameter values that features the convenience of a depressible switch while still identifying the group selected without the shortcomings of panel lamps.